Recently, a dramatic rise in sales of both smart-phones and laptop data cards has resulted in a substantial increase in the amount of data communications passing through mobile telecommunications networks. This volumetric increase can also be attributed to enhancements made to the capabilities of the networks. The most popular use for mobile data is HTTP browsing, although usage of HTTP streaming is growing considerably. Other mobile data uses include HTTP downloading and Peer-to-Peer (P2P) activities such as file sharing.
This ability to use the cellular networks for mobile data services, such as Internet browsing is resulting in subscribers treating their mobile networks in much the same way as they treat their fixed networks. That is, users are tending to expect the same service from the Internet, irrespective of their access method. However, mobile networks have a more restricted capacity and are more costly to operate, as compared to fixed networks.
In this regard, from the network operator's viewpoint, as the mobile broadband traffic volume carried over 2G, 3G, HSPA (High Speed Packet Access) and 4G networks continues to grow, the cost of supporting this data volume is becoming more and more expensive based on the current network architecture and deployments. This cost differential is exacerbated by one of the current business models being utilised, whereby operators charge a flat rate for unlimited amounts of data.
The increased usage is also unfortunately likely to result in an increase of data traffic jams, and hence a degradation of service for mobile users if not properly managed.
It has been proposed to control data-heavy users by “choking” the bandwidth available to them when a maximum data volume limit is exceeded. Whilst this addresses the problem on an individual level, it does not address the network capacity problem as a whole.
It is therefore apparent that mobile broadband is at a crossroads as networks and business models are strained by bandwidth demand that is unmatched by revenue generation.
These problems will only get worse with moves to position mobile data as a replacement for fixed DSL (Digital Subscriber Line) access and with the advent of higher radio access speeds with 4G LTE/SAE (Long Term Evolution/System Architecture Evolution) network. A large percentage of this traffic will consist of data which is destined for the public Internet, a significant proportion of which mobile operators will not be able to add value to, despite carrying the data on their own backhaul transport, core transport or cellular core infrastructure.
In addition to the problems discussed above, conventional mobile telephone communications networks have architectures that are hierarchical and traditionally expensive to scale. Many of the network elements, such as the BTS, routers, BSC/RNC etc are proprietary: devices of one manufacturer often do not interface with devices from another manufacturer. This makes it difficult to introduce new capabilities into the network as a different interface will be required for devices from each manufacturer. Further, conventional base stations are not capable of intelligent local routing or processing. Furthermore, the capacity of existing networks is not always used effectively. For example, many cell sites are under used, whilst others are heavily used.
The current cellular network architecture has the following disadvantages:—                Hierarchical and expensive to scale        Backhaul is a major problem        Proprietary platforms: BTS, BSC/RNC etc        Closed nodes and interfaces        Very limited application or customer awareness (except for QoS priority)        No intelligent local routing or processing        Inefficient use of installed capacity        
There is therefore a need to overcome or ameliorate at least one of the problems of the prior art. In particular there is a need to address the needs of both the network operators and the users in improving the provision of mobile broadband data services.
EP2315412 describes the introduction of a novel platform at the network edge. To open the radio access part a “General Purpose Hardware Platform” may be implemented at the network edge. This may allow operators to split the functions of an Radio Network Controller (RNC) and/or a (e)NodeB between hardware and software. As a consequence operators have the capability to place applications and content directly at the edge of the network.
Despite the capability to place content and applications at the edge, such as games, M2M, CDN or cached content, mandatory core network functions, such as Lawful Intercept (LI), Adult Content Filter (ACF), charging or others, must still be supported.
As content and applications located at different radio locations require the same services and functions located in the core network, the mobile operator has to offer a service parity if a user or machine gets served e.g. content from the e.g. (e)NodeB or the core network. This is seen as one of the major issues in bringing content and applications to the radio locations. The proposed solution should preferably offer all functions and services offered by the core and Gi networks to the customers.
The following known arrangements are, in the majority, disclosed in EP2315412 and will now be described with reference to the accompanying Figures in which:
FIG. 1 illustrates known a high level packet data network architecture, useful for explaining the prior art and embodiments of the present invention;
FIG. 2 illustrates the introduction of a functional “platform” in a 3G network;
FIG. 3 shows the “platform” in more detail provided in the Radio Access Network;
FIG. 4 shows possible locations of the platform within a mobile telecommunications network;
FIG. 5 is a flow chart showing the steps performed when a mobile terminal is activated;
FIG. 6 shows the optimisation of content delivery to a mobile terminal;
FIG. 7 shows a further optimisation of content delivery to a mobile terminal;
FIG. 8 is a flow chart showing the procedures performed when a mobile terminal moves within the network;
FIG. 9 shows the transfer of information between platforms.
In the figures, like elements are generally designated with the same reference numbers.
Key elements of a 3G mobile telecommunications network, and its operation, will now briefly be described with reference to FIG. 1.
Each base station (e.g. Node B 1 and Femto 2) corresponds to a respective cell of the cellular or mobile telecommunications network and receives calls from and transmits calls to a mobile terminal (not shown) in that cell by wireless radio communication in one or both of the circuit switched or packet switched domains. The mobile terminal may be any portable telecommunications device, including a handheld mobile telephone, a personal digital assistant (PDA), machine to machine device (M2M) or a laptop computer equipped with a network access datacard.
The nodeB 1 or Femto 2 can be considered to comprise two main parts: a radio frequency part (radio unit) and a baseband part. The radio frequency part handles the transmission of radio frequency signals between the antenna of the nodeB 1 or Femto 2 and the mobile terminal, and for converting radio frequency signals into digital baseband signals (and vice versa). The baseband part is responsible for controlling and managing the transmission of the baseband signals to other components of the mobile telecommunications network.
In a macro 3G network, the Radio Access Network (RAN) comprises Node Bs and Radio Network Controllers (RNCs). The Node B is the function within the 3G network that provides the physical and transport radio link between the mobile terminal (User Equipment, UE) and the network. The Node B performs the transmission and reception of data wirelessly across the radio interface, and also applies the codes that are necessary to describe channels in a WCDMA system. The RNC is responsible for control the Node Bs that are connected to it. The RNC performs Radio Resource Management (RRM), some of the mobility management functions and is the point where encryption is done before user data is sent to and from a mobile terminal. The RNC connects to the Circuit Switched Core Network through a Media Gateway (MGW) (or MSC/MSS in case of R4 architecture) and to an SGSN (Serving GPRS Support Node) 5 in the Packet Switched Core Network. In FIG. 1, Node B 1 is controlled by RNC 3 across the Iub interface. An RNC may control more than one node B.
FIG. 1 also illustrates a Femto 3G RAN, with Femto 2 operating as the base station. Femto 2 is connected to an Access Gateway (AGW) (a.k.a Concentrator) 4 via an luh interface. Femto is an abbreviation of “femto-cells”, and many other different names have been used, including home access points (HAPs), access points (APs) and femto-base stations, but all names refer to the same apparatus.
The radio link between the Femto 2 and the mobile terminal uses the same cellular telecommunication transport protocols as Node B 1 but with a smaller range—for example 25m. The Femto 2 appears to the mobile terminal as a conventional base station, so no modification to the mobile terminal is required for it to operate with the Femto 2. The Femto 2 performs a role corresponding to that of Node B 1 in the macro 3G RAN.
The Femto 2 would typically be configured to serve a home or office, in addition to GSM/UMTS/LTE networks. The WLAN could belong to the subscriber of the mobile terminal, or be an independently operated WLAN. The owner of Femto 2 can prescribe whether it is open or closed, whereby an open AP is able to carry communications from any mobile device in the GSM/UMTS/LTE network, and a closed AP is only able to carry communications from specific pre-assigned mobile devices.
Conventionally, in a 3G network (macro or Femto), the RANs are controlled by a mobile switching centre (MSC) and an SGSN (Serving GPRS Support Node) 5 of the core network. The MSC supports communications in the circuit switched domain, whilst the SGSN 5 supports communications in the packet switched domain—such as GPRS data transmissions. The SGSN is responsible for the delivery of data packets from and to the mobile terminals within its geographical service area. It performs packet routing and transfer, mobility management (attach/detach and location management), logical link management, and authentication and charging functions. A location register of the SGSN stores location information (e.g., current cell, current VLR) and user profiles (e.g., IMSI, address(es) used in the packet data network) of all mobile terminals registered with this SGSN. In FIG. 1, since the embodiment is concerned with data transmission, only the SGSN is illustrated as being in communication with RNC 3 and AGW 4, across the Iu interface. The RNC 3 typically has a dedicated (not shared) connection to its SGSN 5, such as a cable connection.
Communications between the AGW 4 and the SGSN 5 are preferably IP based communications, and may be, for example, transmitted over a broadband IP network. Further, the connection between the Femto and the AGW 4 may use the PSTN (Public Switched Telephone Network). Typically a DSL cable connects the AGW to the PSTN, and data is transmitted there-between by IP transport/DSL transport. The Femto or AGW converts the cellular telecommunications transport protocols used between the mobile terminal and the Femto 2 to the appropriate IP based signalling. The luh interface is similar to RAP with some Femto extensions.
The femto 2 may be connected to the AGW by means other than a DSL cable and the PSTN network. For example, the femto 2 may be connected to the AGW by a dedicated cable connection that is independent of the PSTN, or by a satellite connection.
The SGSN 5 is in communication with the GGSN 6 (Gateway GPRS Support Node) across the Gn interface. The GGSN is responsible for the interworking between the GPRS network and external packet switched networks, e.g. the Internet. The GGSN enables the mobility of mobile terminals in the networks. It maintains routing necessary to tunnel the Protocol Data Units (PDUs) to the SGSN that service a particular mobile terminal. The GGSN converts the GPRS packets coming from the SGSN into the appropriate packet data protocol (PDP) format (e.g., IP or X.25) and sends them out on the corresponding packet data network. In the other direction, PDP addresses of incoming data packets are converted to the mobile network address of the destination user. The readdressed packets are sent to the responsible SGSN. For this purpose, the GGSN stores the current SGSN address of the user and their profile in its location register. The GGSN is responsible for IP address assignment and is the default router for the connected mobile terminal. The GGSN also performs authentication and charging functions. Other functions include IP Pool management and address mapping, QoS and PDP context enforcement.
In turn the GGSN 6 may route data via any applicable Value Added Service (VAS) equipment 7, before data is forwarded towards its intended destination via the Internet 8. As an example of the functionality of the VAS equipment, the traffic may be inspected for adult content before reaching the end-user if this user is under 18 years of age.
For billing purposes, for example, a PCRF (Policy and Charging Rules Function) apparatus 9 is also provided, in communication with the GGSN 6.
The SGSN 5, GGSN 6, VAS 7 and PCRF apparatus 9 comprise the core network of the mobile telecommunications network. The core also comprises further elements, such as the HLR is (which is not shown).
Mobile telecommunications networks have an active state of communication with their mobile terminals and an inactive/idle state of communication with their terminals. When in the active state, as the mobile terminals move between different cells of the network, the communication session is maintained by performing a “handover” operation between the cells. In the inactive/idle state, as a mobile terminal moves between different cells of the network the mobile terminal performs “cell reselection” to select the most appropriate cell on which to “camp” in order that the mobile terminal can be paged by the network when mobile terminating data is destined for that mobile terminal.
Conventionally, the mobile terminal or network determines whether a handover/cell reselection procedure should be triggered in dependence upon measurements of the radio signals of the cells in the region of the mobile terminal. A filter is applied to the signals (either by the network or by the mobile terminal) which calculates an average (e.g. arithmetical mean) value of these signals over a particular time period. The filtered/average values of the cells are then compared with each other or with a threshold value. In dependence upon these comparisons, cell reselection/handover related procedures are triggered. This cell reselection/handover process generally comprises taking radio signal measurements of neighbouring cells and comparing these to each other and to the radio signal of the current cell to determine which cell provides the best signal strength/quality. Handover/reselection to the best cell can then occur.
Generally calculations to determine whether to perform a handover from one base station to another base station are performed by the network, whereas calculations whether to perform cell reselection are performed by the mobile terminal.
Data in a mobile telecommunications network can be considered to be separated into “control plane” and “user plane”. The control plane performs the required signalling, and includes the relevant application protocol and signalling bearer, for transporting the application protocol messages. Among other things, the application protocol is used for setting up the radio access bearer and the radio network layer. The user plane transmits data traffic and includes data streams and data bearers for the data streams. The data streams are characterised by one or more frame protocols specific for a particular interface. Generally speaking, the user plane carries data for use by a receiving terminal—such as data that allow a voice or picture to be reproduced—and the control plane controls how data are transmitted.
In addition to the elements and functions described above, mobile telecommunications networks also include facilities for transmitting SMS messages. SMS messages are transmitted over the control plane only (and not the user plane).
This architecture is what currently is being used to carry all packet data to and from mobile terminals. That is, in today's implementation of the Packet data architecture, user plane traffic traverses across all the network elements shown between the Node B or Femto on which the user is camped and the internet. That is, all data is directed from the applicable RAN through the core network components SGSN, GGSN and VAS before reaching the internet. All PS traffic accordingly follows the same path and therefore has the same network costs. All applications are processed on the client (on the mobile device) or on the server (which is connected to the internet), and the network core therefore acts like a bit-pipe in the current architecture. For data, where the mobile network operator cannot add any value by carrying it on its own backhaul transport, core transport or cellular core infrastructure (the core network), such as data destined for the public internet without required intervention from the core network, there is no benefit to routing this data via the core network.
However, a large percentage of this traffic can be handled in a more intelligent manner for example through content optimisation (Video & Web), content caching, or locally routed or directly routing content to the public Internet. All these techniques reduce the investment required by a mobile operator to carry the data on its own backhaul and core transport or cellular core infrastructure.
In order to offer low cost packet data, to support new services and to manage customer expectation, a step-change reduction in the end-to-end cost per bit is required.
Mobile operators want to reduce their packet data handling costs through alternate network architectures based on commoditised IT platforms, breaking away from the traditional architecture based on their voice legacy. These new network architectures overcome the Access architecture issues of today
In order to successfully offer cheap packet data and be able to compete with the fixed broadband offers (flat fee) a solution is proposed which focuses on the reduction of the end-to-end cost per bit, especially for Internet access service.
This enables mobile operators to reduce packet data handling costs by means of an alternative network cost model architecture, which breaks out of the traditional network architecture and nodes and utilises lower cost transport networks to optimise the data flow.
In this regard, FIG. 2 shows a high level description of the architecture that may be adopted to deploy this on a 3G network. Such an architecture is described in EP2315412.
According to this arrangement, novel “platforms” (control units/means, also referred to as “SAVi”) 24, 25, 26 for performing functions such as caching, routing, optimisation and offload/return decision functionality are integrated into the network. This decision functionality may be incorporated in the radio architecture. In this regard, the platforms 24, 25, 26 may be incorporated into the NodeBs 1 (25), RNCs 3 (26) or exist as separate physical entities (24). It is these platforms 24, 25, 26 that, for example, determine the path of communications originating from the mobile terminals.
The exact placement of the platform 24, 25, 26 is not essential, and, for a macro 3G network, it can be placed at or between the Node Bs and the RNCs, and also between the RNCs and the SGSNs (or any combination thereof). It would also be possible to place the platform 24, 25, 26 at the GGSN or P-GW.
In the 3G Macro network, the aim is to offload a high percentage of the macro network traffic from the core and transport (IuPS, Gn, etc) by diverting specific traffic type for certain user(s) class directly to the Internet.
Where the platform 24, 25 is located in the Node Bs (or on the Iub interface), it may be possible to redirect the data from all the remaining mobile network elements (e.g. the RNC, SGSN, GGSN and VAS for macro 3G), and sending the data directly to the Internet 8. In a similar manner, where the platform 26 is located at the RNC (or on the Iu interface), it becomes possible to redirect the data from the SGSN 5, GGSN 6 and the VAS 7. The alternative data route is preferably a DSL using ADSL.
It is also preferable to aggregate the alternative data routes for each cell, where applicable. In this regard, each cell will have at least one RNC 3 and a plurality of Node Bs, so where the decision blocks are situated at or in the vicinity of the Node Bs, for instance, there will be a plurality of links which should ideally be aggregated before being passed to the Internet 8. At the point of this aggregation 42, there is preferably a further decision block which enables data to be returned to the legacy route. For instance, a new policy rule may have been implemented, which requires or enables previously offloaded data to be returned to the core network route. This new policy rule may be communicated to the return decision module by the core network policy module. In FIG. 2, this returning of data is only shown to the VAS 7, but the data may be returned to one or more of the other core network elements.
Each of the NodeBs 1 is connected to the mobile network core through a Point of Concentration (PoC) 27. All traffic from the NodeBs 1 which is to be routed through the core mobile network is routed to the PoC 27. This includes both user plane and control plane data. On the control plane level, the PoC 27 routes data to and from the SGSN 5 and the GGSN 6. Control data is also sent to and from other core network components, including the Lawful Interception Database (LI DB) 30, DNS Server 32, Policy Server 9 (including Charging rules and IT Network 9A) and Home Location Register/Home Subscriber Server (HLR/HSS) 36 (which contains subscriber and device profile and state information).
User plane data is transmitted by the PoC 27 to the SGSN 5 and the GGSN 6. From the GGSN 6, data is routed across a VAS 7 node to the Internet 8. In 3G this is the standard data path from the mobile terminals to the Internet.
The embodiment of FIG. 2 is in relation to a 3G network. Embodiments of the invention are equally applicable to 4G (LTE/SAE) networks.
The LTE/SAE macro network includes eNode Bs which make up the RAN. The eNode Bs effectively combine the functionality of the node B and the RNC of the 3G network. These eNodeBs are the network components which communicate with the mobile communication devices. It is envisaged that the eNodeBs will be arranged in groups and each group controlled by a Mobility Management Entity (MME) and a User Plane Entity (UPE).
The MME performs many of the mobility functions traditionally provided by the SGSN. The MME terminates the control plane with the mobile device. It is responsible for terminating NAS (Non Access Stratum) Signalling such as MM (Mobility Management) and SM (Session Management) information as well as coordinating Idle Mode procedures. Other responsibilities of the MME include gateway selection inter MME Mobility and authentication of the mobile device.
The UPE manages protocols on the user plane such as, storing mobile terminal contexts, terminating the Idle Mode on the user plane, and PDP context encryption.
The platforms would operate in the same manner as described in relation to the 3G network. The platforms may be located at many different locations in the 4G network.
Arrangements in which the Radio Access Network controls the use of resources by mobile terminals will now be described.
Platform Architecture
As discussed above, a mobile telecommunication network is modified by the introduction of a “platform” 24,25,26. Such a platform (or control unit/means, also referred to as “SAVi”) is shown in more detail at 700 FIG. 3 and which includes three principal parts: soft nodes 702 (physical/transport layer), network functions 704 and services 706 (application layer).
The platform 700 communicates with the radio frequency/RF part (radio unit) of a base station, such as a NodeB 1. The soft nodes 702 of the platform 700 comprise components such as a soft NodeB 708, soft BTS 710, soft eNodeB 711 and soft RNC 712 and soft SGSN/GGSN 714. The soft nodeB 708 provides functions equivalent to the baseband part of a conventional NodeB in a 3G telecommunications network. The soft BTS 710 provides baseband functions equivalent to the baseband functions of a BTS in a conventional 2G mobile telecommunications network. The soft enodeB 711 provides baseband functions equivalent to the baseband functions provided by a conventional enodeB in a 4G mobile telecommunications network. The platform 700 may therefore communicate with the radio frequency part of a 2G, 3G or 4G base station and provide appropriate baseband services for 2G, 3G or 4G technologies (or indeed for other technologies). A 3G mobile terminal that wishes to obtain telecommunication services from the mobile telecommunications networks connects wirelessly to the radio frequency part of a NodeB. Baseband functions may be provided either by a baseband part of the conventional NodeB or by the soft NodeB 708 forming an element of the soft node part of the platform 700. For example, the soft NodeB 708 may receive radio measurements from the radio frequency part of the NodeB to which it is connected, and may provide these radio measurements to other elements of the platform 700.
The network functions part 704 of the platform 700 includes modules for performing functions similar to those performed by the core network of a mobile telecommunications network, such as billing 720, location tracking 722 and the radio resource management (RRM) 724. The network functions may further comprise an offload decision module 726 that performs a function similar to the offload decision modules 24, 25 and 26 described above. The network functions part 704 may further comprise a caching function 728 and Content Delivery Network function 730.
The network functions part 704 of the platform 700 provides an Application Programming Interface (API) framework to the services part 706 of the platform 700. The services part 706 of the platform supports a plurality of applications 740, 742 etc.
The network functions fall into three main categories, those that enable the network operation (e.g. charging, O&M), those that support service operation (e.g. Location) and those that optimise the usage of the network by certain applications and services (e.g. Caching, Video Optimisation).
The applications supported on the Platform 700 are the entities that supply or demand the flow of data on the network, akin to a server on the internet, e.g. gaming server, navigation server.
The API is implemented by a software program running on the network function part 704 which presents a novel standardised interface for the applications 740, 742 etc of the services part 706. The novel standardised API provides a consistent interface, defining communication protocols, ports etc. Full details of the API may be published to allow a multiplicity of applications to be developed for the platform 700 by multiple developers. This should be contrasted with prior art arrangements where each component of a mobile telecommunications network (such as BTS, BSC/RNC, SGSN etc) is proprietary and tends to have a unique interface, meaning that a different application must be written for each node of a conventional network.
The applications 740, 742 etc may provide services to users of the telecommunications network by co-operating with other parts of the platform 700.
The details of the use of each application used by a user of the mobile telecommunications network are stored in an application context/container. The Application context contains application names, protocol used to carry such application, their characteristics that are measured/reported over period of time and some statistical information about these applications (volume, number of users using these applications, etc.).
As shown in FIG. 4, a platform 700 may be provided at each base station of the mobile network (where it is connected to the radio frequency part of the base station—NodeB 1 in FIG. 2), forming an access node 800. Platform 700 may also be provided at the RNC (item 3 in FIG. 2) where it forms a gateway 802. The access node 800 and the gateway 802 are both configured to communicate directly with the network core 804 (for example, comprising the SGSN 5, GGSN 6 and VAS 7). The access node 800 and gateway 802 may also be connected to the internet 8 for direct internet access via direct links 806 and 808, respectively, such that at least a portion of the core network 804 is bypassed in the manner described above.
The following are examples of access technologies that can be provided within the access node 700:
3GPP: GSM/GPRS, UMTS/HSPA & LTE
IEEE: 802.11 family & 802.16 family
ITU: DSL, ADSL, VDSL, VDSL2
Allocation of Functions to Platforms
The steps performed when a mobile terminal is activated at a NodeB, at the Femto or at the Access Point (AP) of the network which includes the novel platform 700 will now be described with reference to FIG. 5. At step 9A the mobile terminal (UE) is activated within the coverage area of a particular NodeB, at the Femto or at the AP. The access part of the NodeB, at the Femto or at the AP communicates information from the mobile terminal to the platform 700 associated with the NodeB, at the Femto or at the AP. At step 9B the platform 700 then allocates the baseband NodeB, at the Femto or at the AP function and the RNC or BRAS (Broadband Remote Access Server) function either at access node 800 at the NodeB at the Femto or at the AP site or at the gateway 802 at the RNC or BRAS site of the network or even from neighbouring nodes that have spare resources to pull. The decision as to whether the RNC or BRAS function is allocated at the platform 700 of access node 800 or the gateway node 802 may be made depending on various criteria, including:                The device type—for example this decision can be based on the radio access capabilities that the mobile terminal indicates upon activation, such as whether it is operating in the circuit switched or packet switched domains.        The location of the mobile terminal. If the mobile terminal is near the edge of the cell (which can be determined by network power measurements or neighbour cell measurements from the mobile terminal, within a plus or minus 3 dB range for the RACH).        The establishment cause of the connection request: such that the NodeB can filter the unnecessary signalling information from the mobile terminal which is not critical—for example periodic routing area update messages.        
Upon allocating the baseband NodeB at the Femto or at the AP and the RNC or BRAS function, the NodeB at the Femto or at the AP may allocate the mobile terminal to a particular carrier dedicated to the RNC or BRAS function.
Once the RNC or BRAS function is allocated to either the access node 800 or the gateway 802 at step 9C, other functions performed by the platform 700 at the access node 800 (or other access node) and the gateway 802 (or other gateway) are allocated to the mobile device. All other platform functions may be provided by the platform where the RNC or BRAS function is allocated to the mobile terminal. However, a platform at a different location to that which provides the RNC or BRAS function to the mobile terminal may provide some or all other functions.
At step 9D the platform which is allocated the RNC or BRAS function is provided with a Common ID message from the core network 804.
At step 9E, this message is used by the platform 700 to look up the complete subscription information for the mobile terminal, as well as the resource requirements (QoS) of the services required and negotiated PDP context, this information being provided by the core network 804.
The subscription information relating to the device that is obtained from the central nodes (e.g, core network) 804 is used to allocate the other functions at access node 800 and/or the gateway 802 in dependence upon various factors, including:
Detailed information regarding the mobile terminal type obtained from the core network.
The subscription characteristics of the mobile terminal.
The applications previously used most frequently by the mobile terminal.
The characteristics of the applications previously used by the mobile device and the performance requirements thereof.
The historic mobility of the mobile terminal (speed, connection, distance travelled etc).
The location of the mobile terminal and the likely destination of traffic from the mobile terminal based on historic usage patterns.
The load of the NodeB providing RF services to the mobile terminal, and the historic traffic trends at that NodeB at Femto or at AP.
The characteristics of the NodeB at the Femto or at the AP providing RF services (for example, the location, what other devices are connected through the NodeB at the Femto or at the AP, the number of machine to machine devices being attached and served by the NodeB, etc).
As mentioned above, a single mobile terminal may have platform functions/applications allocated on a plurality of platforms. Generally, when a mobile terminal is near-stationary it is most efficient for its functions/applications to be served from an access node 800 (i.e. distributed), whereas mobile terminals with greater mobility (or lower anticipated cell hold times) will be most efficiently served by having fewer or no functions/applications served from the access Node 800, and more or all functions/applications served from a gateway 802 (i.e. centralised). The assignment of functions/applications to a mobile terminal between an access node 800 and a gateway 802 will also depend upon the characteristics of the service type provided by the application (for example, the average IP session duration, the popularity of the particular application, the average mobility of mobile terminal using the service provided by the application etc).
Traffic management may be performed at the access node 800, where there is access to real-time radio information from the radio frequency part of the NodeB, the Femto or the AP serving the mobile device.
Centralised Radio Resource Management (RRM) may be provided at the gateway 802, and maintains performance across different access modes 800, which may have different radio access technologies, frequency bands, coverage etc. The RRM function 724 of the platform 700 of the gateway 802 may obtain information regarding radio traffic management from each access node 800 to dynamically position subscribers to particular radio technology. This technique will be used to allocate network resources based on the resource availability, application used and user mobility, For example, the traffic management information may be provided by the soft NodeB 708, Femto or AP of the platform 700 at the access node 800. This soft NodeB 708 obtains radio information relating to the mobile terminal from the radio frequency part of the NodeB to which the mobile terminal is wirelessly connected.
For a particular mobile terminal, functions provided by an access node 800 and gateway 802 may be coordinated to work together in an advantageous manner (i.e. a hybrid or distributed arrangement). For example, the gateway 802 may set operating limits or ranges within which functions performed by the access node 800 may be performed, without reference to the gateway 802. When the functions move outside the ranges set, control of those functions may be passed to the gateway 802.
Further, the access node 800 and the gateway 802 may cooperate to advantageously optimise content delivery to a mobile terminal.
The optimisation of content delivery will now be described with reference to FIG. 6 of the drawings. Content may be optimised at gateway 802 and at an access node 800. The gateway 802 may serve multiple access nodes 800, and my distribute content to those multiple access nodes 800, for onward transmissions from each of those access nodes 800 to a mobile terminal via the radio frequency part of NodeB, the Femto or the AP serving that node. Radio quality measurements are reported by the mobile terminal to the access node 800 at regular intervals, such as 2 millisecond intervals. Radio quality measurement relating to that mobile terminal are transmitted between the radio frequency part of the NodeB, the Femto or the AP serving the mobile terminal to the access node 800 at regular intervals, such as between 2 and 10 millisecond intervals. These radio measurements are received at the soft nodes 702 and are passed to functions 704 (e.g. to QoS function 732 for analysis). These radio frequency measurements from the mobile terminal and the NodeB are reported by the access node 800 to the gateway 802 (e.g. to QoS function 732 of the gateway 802 for analysis) at regular intervals, such as intervals of between 1 and 10 seconds. The gateway 802 may receive radio information from multiple access nodes 800. The radio measurements received by the gateway 802 may be analysed over a relatively long period, such as between 1 and 2 minutes. The radio quality measurements may be averaged (for example, the arithmetical mean of the radio quality may be determined) over this time period. The transmission of content from the gateway 802 may then be optimised according to this calculation. Where the content is distributed by the gateway 802 to a plurality of access nodes 800, the content distribution will be based on the analysis of the radio quality indicators from all of the access nodes 800. The analysis may consider the maximum or peak radio performance over the time period of between 1 and 2 minutes.
When the content is received by each access node 800, the access node 800 then distributes the content to each mobile terminal. This distribution is optimised based on real-time network mode and mobile terminal specific radio link quality, as determined over a period of, for example, between 1 and 10 milliseconds. That is, content delivered to a mobile terminal that has high radio link quality may be optimised in a different manner to a mobile terminal that had poor radio link quality.
The co-operation between access nodes 800 and gateways 802 may further enhance the distribution of content in a manner now to be described with reference to FIG. 7.
When a mobile terminal requests a particular content item, this request is transmitted to the access node 800 serving that mobile terminal, assuming that this is the first request for this content item to the access node 800, the access node 800 passes this request to the gateway 802 serving the access node 800. Assuming that this is the first request for this content item from the gateway 802, the gateway 802 retrieves the content from a content server. The content is then provided by the content server to the gateway 802, and from there is distributed to the access node 800, and onwardly to the requesting mobile terminal. Advantageously, the gateway 802 maintains a record of content items that are requested frequently. When a content item is determined by the gateway 802 to be requested frequently, this is stored in a cache 1110 associated with the gateway 802 (which may be the cache 728 of the platform 700). Subsequent requests for that content item from access nodes 800 to the gateway 802 can then be serviced by retrieving the content item from the cache 1110 and distributing the content item to the requesting access node 800, and thus avoiding the need to request the content from the content server.
The gateway 802 may be further configured to identify popular content items that are likely to be requested by a large number of access nodes 800. When it is determined that a content item is popular, the gateway 802 may push these content items to each of the access nodes 800 associated therewith (so that this content is hosted at the access node 800, using Content Delivery Network (CDN) function 730 of the network functions 704 of the gateway 802 and the access node 800). The content is then available at the access node 800 for transmission to any mobile terminal that requests it, without having to retrieve this content from the gateway 802 or the content server. Advantageously, the distribution of such content items is performed in a manner which takes into account the capacity or the congestion of the link between the mobile terminal and the gateway 802 and the nature of the content. For example, typically a link between a mobile terminal and the gateway 802 may experience very little usage and congestion in the early hours of the morning. The content item can be advantageously transmitted in between the gateway 802 and the access node 800 at this time, when there is spare capacity. The gateway 802 will determine whether the content item is suitable for transmission on this basis, for example, by taking into account a number of times that the content item has been requested, the size of the content item and the storage space at the access node 800. If a content item is relatively small and is time-critical, such as news headlines, then such a content item may be distributed frequently throughout the day, as such content is not suitable for transmission once a day at early hours of the morning, as it becomes quickly out of date.
Relocation of Mobile Terminal
The procedures performed when a mobile terminal moves between cells in the mobile telecommunications network will now be described with reference to FIG. 8. In the conventional manner at step 12A, when the mobile terminal moves to the edge of its current serving cell, the radio measurements reported from the mobile terminal and the radio frequency part of the NodeB, the Femto or the AP serving that mobile terminal are used by the core network to determine when to perform a handover and to which target cell the handover should be performed. When the best target cell has been identified, handover to that target cell from the serving cell it is performed at 12B in a conventional manner.
At step 12C selected platform functions may be relocated from the source access node (that served the old cell) to the destination access node (that serves the new target cell).
When the source and destination access nodes are served by the same gateway, only base station function (such as soft NodeB functions 708) may be relocated to the destination access node.
The relocation of functions of the access nodes is performed independently to the radio handover, so for some time after the radio handover, the source access node continues to serve content to the mobile terminal through the destination access node. The routing of data packets for the 3G network between the destination and the source access nodes may be performed using an Iu interface between the RNC or BRAS function 712 of the destination access node and the SGSN/GGSN function 714 of the source access node. Alternatively, the routing of data packets between the destination and the source access nodes can be completed by the SGSN/GGSN function 714 of the destination access node connecting directly to functions of the source access node through an IP interface.
After handover has been completed at step 12B, the access node controlling the mobile terminal may be relocated from the source access node to the destination access node in coordination with the gateway. the standardised handover decisions (mainly based on coverage, quality, power, interference, etc.) for 2G, 3G, LTE & fixed network are used to move the mobile from one node or system to another. However, the platform 700 introduces new opportunity to make the handover decision based on type or characteristics of the certain application, type of user and the QoS requirements.
The timing of the relocation of access node functions from the source to destination platform may be dependent on the following:                the duration of the current connection/communication of the mobile terminal        the speed of movement of the mobile terminal        the characteristics of the applications being used by the mobile device, the quality of service, the predicated type and amounts of transmission ongoing.        The radio resource allocations status at the mobile terminal        The respective node of the source and destination and access nodes.        
At step 12D, optionally, some functions will be reallocated from the access nodes to the gateway. For example, if the destination access node is heavily loaded and is congested, or has a lower capability then the source access node, or the mobile terminal is determined to be very mobile, it may be advantageous to transfer functions to the gateway. Functions are reallocated from the access node to the gateway by, for example, a Serving Radio Network Subsystem (SRNS) relocation between the RNC function 712 of the access node and the gateway. Alternatively the functions may be reallocated by performing a radio reconfiguration of user connection to the mobile terminal.
The reallocation of functions from an access node to the gateway may be performed at call/communication sessions set-up. At call/communication session set-up, further subscriber information will be provided, which may be used by the access node or gateway to be determine whether it would be advantageous to reallocate functions from the access node to the gateway. Reallocation of functions from the access node 800 to the gateway 802 may be performed during an active connection when a requirement of the communication sessions has been modified, or where the required resource is not available at the access node 800.
According to the same principles, applications may be (re)located (or distributed) between access nodes 800 and for gateways 802 to provide optimised application delivery/best use of the communication resources.
As mentioned above, information about each application used by the user at the mobile terminal is stored in an application context. The application context is shared between each access node 800 and gateway 802 that control the user connection for that mobile terminal. One of the access nodes 800/gateways 802 will be the “master” for that particular application, and that will also be the master of an application specific record in the application context. The application context is advantageously periodically synchronised between the access node 800 and the gateway 802.
The application information is the application context specific to a particular mobile terminal, and this is passed between access nodes and gateways during reallocation for a mobile terminal, enabling the application to be seamlessly passed access nodes/gateways, avoiding impacts to the user experience.
FIG. 9 shows the transfer of application information between access nodes and gateways.
Tailoring Bandwidth to Application
Radio measurements received from the radio frequency part of the NodeB, the Femto or the AP serving the mobile terminal are passed to the soft nodes 702 of the platform 700 (of the access node 800 or gateway 802 serving the mobile terminal), and are passed to the network functions 704 of the platform 700, which then distributes the measurements to where necessary within the platform 700. The platform 700 has access to the subscriber information from the core network, which allows the network functions 704 to deliver data traffic in a manner that is optimised for radio conditions as indicated by the radio measurements. The data traffic may also be optimised according to the subscription of the user of the mobile terminal available radio resource, mobile terminal capability, and/or for the class of the terminal (e.g. access technologies used). This optimisation allows bandwidth usage to be balanced with customer experience. The subscriber information may include information about the price plan of the user of the mobile terminal. The mobile network operator may track the type of application used by the user, the total data usage of the user, and may differentially target radio resources the highest data value stream of users.
By hosting applications 740, 742 in the services part 706 of the platform the access node 800 (or at least the gateway 802), the point of the network that is aware of the application being used by the user of the mobile terminal closer in the link between the mobile terminal and the core network to the NodeB serving the mobile terminal. This enables the sharing of network resources to the most appropriate data streams, such as the most profitable data streams. Such awareness of the application to which a request for data transmission relates allows the use of low value data streams, such as peer-to-peer file sharing, to be allocated only limited bandwidth, so that remaining bandwidth can be targeted to particular users. In the uplink, transmission of data can be controlled by the access node 800 (or gateway 802) hosting the application to control data flow appropriately before data is onwardly transmitted towards the core of the network (which was not possible with conventional arrangements).
Application Programming Interface (API)
As mentioned above, a novel API is provided which defines the language that each of the software modules 740, 742 of the platform 700 use to communicate to coordinate to optimise application delivery to users. The platform 700 negotiates which each application 740, 742 the specific resource and performance requirements based on the application characteristics, allowing the application to directly communicate the scheduling performance requirements, rather than using a predefined set of quality of service parameters. This negotiation between the platform 700 and the applications 740, 742 is facilitated by the API.
The API may also facilitate the provision of radio link quality information (e.g. from QoS function 732) to applications 740, 742.
The API may further enable the platform 700 to control use of the applications 740, 742—e.g. to allow, disallow or adapt the applications.
By way of example, the application 740 may be a Voice over IP (VoIP) application. The nature of Voice over IP communications is that there is a virtually continuous succession of small data packets in which voice data is communicated. The voice data must be communicated with no or minimal latency in order that a two-way conversation can be performed successfully. The Voice over IP application 740 is able to compress voice data before transmission using a variety of techniques/CODECs. The compression techniques/CODECs may range from a relatively low compression technique, which provides high quality voice reproduction but requires a large bandwidth, to a much higher compression technique which provides reduced voice quality and which requires a much lower bandwidth.
The API is operable to provide details of the application characteristics to the network functions part 704 of the platform 700. This makes the network functions part 704 of the platform aware of the characteristics of the application. In the present example, as the application is a Voice over IP application, the network functions part 704 may be made aware that the application will tend to transmit continuous successions of small data packets that require transmission with no or low latency. The network function 704 may then be configured appropriately.
The API may further be operable to allow the network functions part 704 to communicate radio link quality information to the application 740. For example, when the network functions part 704 received information regarding the application characteristics (via the API), it may allocate radio link resources to that application 740. This allocation of radio link resources may be communicated by the network functions part 704 to the application 740 (via the API). The application 740 may then select an appropriate compression technique/CODEC in dependence upon the radio link quality available. During a Voice over IP call, the available radio link quality may be communicated regularly from the network functions part 704 to the application 740 (via the API) to allow the application 740 to vary the compression technique/CODEC used in accordance with changes to the radio link quality.
The network functions part 704 may control how the applications 740, 742 work (via the API). The network functions part 704 may allow, disallow or adapt the applications 740, 742 hosted in the services part 706 of the platform 700. For example, the network functions part 704 may require the Voice over IP application 740 to use a particular compression technique/CODEC if radio link bandwidth is restricted.
Another example of how the network functions part 704 may advantageously provide radio link quality information to an application (via the API) is when the application 742 is a gaming application used by several users. If the radio link quality information received by the application 742 indicates that bandwidth is restricted, the application 742 may adapt is communications to the users such that latency of the communications is increased uniformly for all of the users (so that they all experience the same delay), in order that each of the users is provided with the same gaming experience.
In the arrangements described, the devices that connect to the platforms 700 are mobile devices that connect to the platforms via the radio access network of a mobile/cellular telecommunications network. It should be appreciated that non-mobile (fixed) devices may be connected to the platforms 700, for example by a wired or cable connection.
Allocation of Services
The control means is responsible for allocating the service instance for each UE, based on the UE locations and the control means capacity, capability and available resources to host another instance of a service. The UE is using service but the User (MSISDN) gives access to specific services.
For certain low popularity services or where the available serving control means capacity or capability is limited, the service can be hosted from a central control means, or from a neighbouring distributed control means.
For some services/functions, where the source and destination client applications are in the same geographical region, being served by the same site (e.g. BTS location) or site cluster (e.g. finite number of sites), the access node 800/gateway 802 ensures that the server for the service is located close to both users, and the traffic is routed between the users within the site.
The arrangement described above in relation to FIGS. 1 to 9 is the subject-matter of EP2315412. Such an arrangement deals with LI and other core network functions by always routing traffic that must be subject to LI and other core network functions through the core network, or by providing LI and other core network functions functionality at the network edge.
An alternative known representation of the platform 700 is shown in FIG. 10. The platform 700 includes a platform core 1000 which communicates based on two sets of APIs:                Application APIs 1010—which, as discussed above, offers standardised hosting environment for applications providing communication to Service Software 741, 742 and Network Functions Software 1015, 1016 hosted on the platform 700.        Network APIs 1017—which provide control and connectivity to network nodes 1030 through a vendor specific Adaptors 1020; Network API defines standardised communication between core 1000 and the Adaptors 1020; Communication between Adaptor 1020 network nodes and 3GPP/LTE node, such as (e)NodeB 1, BBU 1032, RNC 3, SGSN 5, GGSN 6/P-GW and MME 1040, remains proprietary        
The Platform 700 includes common network functions Software 1015, 1016 such as Scheduling, Routing, Billing/accounting, security and Policy functions, which allow the architecture to offer seamless experience across the network. The Platform 700 will provide capability to meet the Lawful Intercept (LI) requirements.
The Adaptors 1020 translate the Vendor specific implementation on the 3GPP/LTE nodes 1030, such as eNB, BBU, RNC, SGSN, GGSN/P-GW and MME, to common and open interface to the environment of platform 700.
The Adaptor 1020 for each 3GPP/LTE node 1030, such as eNB, BBU, RNC, SGSN, GGSN/P-GW and MME, is responsible for ensuring communication between the Network API 1017 and 3GPP node is secure.
The Platform 700 provides the capability for some Applications 741,742 hosted in the Platform 700 to be contacted remotely from the platform 700.
Logically control and data traffic interfaces (control plane and user plane) between the physical manifestations of the platforms 700 exist independent of the underlying 3GPP/LTE network nodes 1030. These interfaces will require to be made secure through functionality included within each platform 700.
The Platform 700 also provides the capability for hosted Network 1015,1016 and Service Applications 741,742 on different platforms 700 to communicate and pass data in a secure manner without mandating security to be provided by the application 741,742,1015,1016.
In contrast to the arrangements described above, in this implementation the platform 700 may handle both control and data traffic interfaces (control plane and user plane), rather than just the data traffic/user plane. Further, in contrast to the arrangements described above the nature of the gateway 802 may be different. In the implementation described hereinafter, the gateway 802 may be located other than at the RNC. For example, the gateway 802 may be located at the SGSN 5, GGSN 6, VAS 7 or PCRF apparatus 9, or in any part of the network core or RAN. In the implementation described hereinafter, the gateway 802 may be considered to be an interface between the platforms 700 at the access node (800) and the core network, rather than part of the “control means”.
When the platform 700 environment is introduced into a mobile network it means that traffic can be inserted, hosted or created in the data path between GGSN 6 and UE, potentially impacting the operation of existing core systems (such as charging, policy enforcement & LI from other core network components (Charging rules and IT Network 9A, Policy Server 9 and including the Lawful Interception Database (LI DB) 30—see FIG. 2) which need to be replicated.